From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; rv:1.7.3) Gecko/20041020 Firefox/0.10.1 Description of problem: nsswitch.conf file contains following line for 'hosts' key: hosts: files dns File /etc/hosts contains following lines: 127.000.000.001 localhost localhost.localdomain In such case it is impossible to get any kind of information about hosts listened above. If /etc/hosts is modified as below: 127.0.0.1 localhost localhost.localdomain everythin is ok. 'getent' and 'ping' utilities were used to check whether host information is available or not. Version-Release number of selected component (if applicable): glibc-devel-2.3.3-74 How reproducible: Always Steps to Reproduce: 1. vi /etc/hosts; 2. add '0' up to 3 symbols in every IP address byte (e.g. 127.0.0.1 -> 127.000.000.001); Actual Results: 1. Usinf 'ping': # ping localhost ping: unknown host localhost 2. Using 'getent' # getent hosts < nothing > Expected Results: # ping localhost <something like below> PING fox (127.0.0.1) 56(84) bytes of data. 64 bytes from fox (127.0.0.1): icmp_seq=0 ttl=64 time=0.036 ms 64 bytes from fox (127.0.0.1): icmp_seq=1 ttl=64 time=0.028 ms 64 bytes from fox (127.0.0.1): icmp_seq=2 ttl=64 time=0.034 ms 64 bytes from fox (127.0.0.1): icmp_seq=3 ttl=64 time=0.048 ms 64 bytes from fox (127.0.0.1): icmp_seq=4 ttl=64 time=0.030 ms --- fox ping statistics --- 5 packets transmitted, 5 received, 0% packet loss, time 3999ms rtt min/avg/max/mdev = 0.028/0.035/0.048/0.008 ms, pipe 2 # getent hosts 127.0.0.1 localhost.localdomain localhost Additional info: This unexpected behaviour was found in FC3 only. FC2's libnss_files.so works properly.
127.000.000.001 is not a valid IP address for inet_pton (AF_INET, ...). See http://www.opengroup.org/onlinepubs/009695399/functions/inet_ntop.html The inet_pton() function does not accept other formats (such as the octal numbers, hexadecimal numbers, and fewer than four numbers that inet_addr() accepts). Your IP address has 3 octal numbers and one decimal, therefore it is not accepted.